how to simulate fully differential OTA for transient and step response...please help

[raditsme]

hello all,

i have designed fully differential folded cascode amplifier. i have done its AC simulation (AC response, gain, phase UGB etc.) only.
but don't know how arrange the setup for transient and step response. i want see the settling time etc.

I know how to do it for single ended amplifier...where we have to make unity gain configuration etc. but don't know for Fully Differential Amplifier..?????

Please provide me figure of the setup to do it. I am driving capacitive load and this opamp is to be used in sample and hold application.

Please help.....

 

[ic98]

there are different ways to test settling time of FD OTA,
use flip-around or charge-redistribution configurations for your SHA (find them John&Martin Analog IC book)
as well you can check it out using a FD inverting amplifier configuration..

 

[engasu]

Hi,

I believe this is a very good article that should help you
https://citeseerx.ist.psu.edu/viewd...6BB34709?doi=10.1.1.111.173&rep=rep1&type=pdf

Best,
Essam

 

[erikl]

... don't know how arrange the setup for transient and step response. i want see the settling time etc.
... we have to make unity gain configuration etc. but don't know for Fully Differential Amplifier..?????
Please provide me figure of the setup to do it.

See this answer!

 

[raditsme]

See this answer!

do we really require such a big setup for transient and step response????? it will be very difficult... in single ended it was quite easy...

 

[erikl]

do we really require such a big setup for transient and step response?

I think this has been set up for fully automatic and reproducible characterization. Just pick a min. testbench schematic for your personal needs!

 

[raditsme]

erikl, WOULD U PLEASE HELP BY PROVIDING ME THE SIMPLEST SETUP FIGURE FOR STEP RESPONSE AND TRANSIENT RESPONSE OF FULLY DIFF AMP

 

[erikl]

Just study the C@dence tutorial thoroughly, it's all in there. Understanding the appropriate signal path for the intended analysis is the key for selecting the necessary testbench setup. And that's what you should learn and do yourself!